KR101912270B1 - Common mode filter - Google Patents

Abstract

The present invention relates to a method for manufacturing a thin film transistor, which is capable of ESD protection while achieving thinning of a chip, comprising: a primary coil layer and a secondary coil layer which are electromagnetically coupled; A pair of external terminals connected to an end of the primary coil layer and a pair of external terminals connected to an end of the secondary coil layer; A second ESD prevention member connecting a first ESD prevention member connecting between the pair of external terminals to be energized with the primary coil layer and a pair of external terminals energizing the secondary coil layer; And a ground electrode connecting the first ESD prevention member and the second ESD prevention member, wherein a stepped portion is formed at the center of the ground electrode.

Description

Common mode filter {COMMON MODE FILTER}

The present invention relates to a common mode filter, and more particularly, to a common mode filter having an ESD protection function.

As technology develops, electronic devices such as mobile phones, home appliances, PCs, PDAs, and LCDs are changing from analog to digital, and the speed is increasing due to an increase in the amount of data to be processed. As a result, USB 2.0, USB 3.0 and high-definition multimedia interface (HDMI) have been widely used as high-speed signal transmission interfaces, and these interfaces are currently used in many digital devices such as personal computers and digital high- .

These high-speed interfaces employ a differential signaling system that transmits a differential signal (differential mode signal) using a pair of signal lines unlike a single-end transmission system that has been used for a long time. However, since the electronic devices which are digitized and accelerated are sensitive to external stimuli, signal distortions due to high frequency noise often occur.

In order to eliminate such noise, a filter is installed in an electronic device. In particular, a common mode filter for eliminating common mode noise is widely used in a high-speed differential signal line and the like. Common-mode noise is the noise that originates in the differential signal line, and the common-mode filter removes common-mode noise that can not be eliminated by existing filters.

However, since the recent high-speed digital interface deals with fine signals of high transmission speed, a very sensitive IC for ESD (Electro Static Discharge) (hereinafter referred to as "ESD " Should be used.

Accordingly, a common mode filter provided with an ESD protection layer is proposed in the patent document (KOKAI Publication No. 10-2010-0037000). 3, the ESD protection layer 12b is further provided below the common mode filter layer 12a which functions as a filter. The ESD protection layer is provided with an ESD absorbing layer 30 ). As a result, the overvoltage signal due to the static electricity passes through the gap electrodes 28 and 29 maintaining a predetermined gap from the lead conductors, thereby protecting the helical conductors 17 and 18 of the common mode filter layer.

However, in the case of the common mode filter disclosed in the patent document, since a separate ESD protection layer for ESD protection is provided inside the common mode filter, it is difficult to realize thinning of the chip. The lead conductors holding a predetermined gap from the gap electrodes 28 and 29 are connected to either one of a pair of external terminals (for example, 13a and 13b) on the basis of one helical conductor (for example, 17) It has a disadvantage that ESD protection is not possible when an overvoltage signal is applied to the other external terminal which is connected to the input terminal only and serves as an output terminal.

Patent Document: Korean Patent Publication No. 10-2010-0037000

SUMMARY OF THE INVENTION The present invention provides a common mode filter for solving the above-described problems. The present invention provides a bar-shaped ESD protection member between a coil layer, more specifically, between a via electrode and an external terminal, It is also an object of the present invention to provide a common mode filter capable of protecting a coil layer from an overvoltage signal applied through both input and output terminals by connecting an ESD protection member to both ends of the coil layer.

According to an aspect of the present invention, there is provided a magnetoresistive sensor comprising: a primary coil layer and a secondary coil layer that are electromagnetically coupled; A pair of external terminals connected to an end of the primary coil layer and a pair of external terminals connected to an end of the secondary coil layer; A second ESD prevention member connecting a first ESD prevention member connecting between the pair of external terminals to be energized with the primary coil layer and a pair of external terminals energizing the secondary coil layer; And a ground electrode connecting the first ESD prevention member and the second ESD prevention member, wherein a stepped portion is formed at the center of the ground electrode.

here. Wherein the first ESD prevention member and the second ESD prevention member are formed in the form of a bar.

Also, the common electrode filter is formed in the form of a bar having a stepped portion at the center.

The common mode filter is further provided with a magnetic resin composite around the ground electrode including a recessed space formed by the stepped portion of the ground electrode.

According to another aspect of the present invention, there is provided a magnetic recording medium comprising: an insulating layer provided on a magnetic substrate and including a primary coil layer and a secondary coil layer that are electromagnetically coupled to the inside of the magnetic substrate; A pair of external terminals provided on the insulating layer and connected to ends of the primary coil layer via via electrodes, and a pair of external terminals connected to ends of the secondary coil layer; A second ESD prevention member connecting a first ESD prevention member connecting between the pair of external terminals to be energized with the primary coil layer and a pair of external terminals energizing the secondary coil layer; And a ground electrode provided on the insulating layer and connecting the first ESD prevention member and the second ESD prevention member, wherein a stepped portion is formed at the center of the ground electrode.

Here, the first ESD prevention member and the second ESD prevention member are disposed in parallel, and the ground electrode is disposed to cross between the first ESD prevention member and the second ESD prevention member.

And, the first ESD prevention member and the second ESD prevention member are provided between the via electrode and the external terminal.

Also disclosed is a common mode filter in which a magnetic resin composite is provided around the ground electrode and the external terminal including a recessed space formed by the stepped portion of the ground electrode.

Further, the magnetic resin composite is formed to have the same height as the ground electrode and the external terminal.

Further, a stepped portion of the ground electrode is formed at a position corresponding to the center core portion of the first and second coil layers.

According to the common mode filter of the present invention, it is advantageous to realize a thinner film than the conventional common mode filter, and it is possible to protect the coil layer against an overvoltage signal applied from either of the input / output external terminals.

1 is an external perspective view of a common mode filter according to the present invention;
2 is a top view of a common mode filter according to the present invention;
3 is a cross-sectional view taken along the line I-I '
4 is a cross-sectional view taken along the line II-II '
5 is a cross-sectional view taken along line III-III '
6 is a top view of the common mode filter according to the present invention before the formation of external terminals
7 is a top view of the common mode filter according to the present invention before forming the magnetic resin composite

The advantages and features of the present invention and the techniques for achieving them will be apparent from the following detailed description taken in conjunction with the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. The present embodiments are provided so that the disclosure of the present invention is not only limited thereto, but also may enable others skilled in the art to fully understand the scope of the invention.

The terms used herein are intended to illustrate the embodiments and are not intended to limit the invention. In this specification, the singular forms include plural forms unless otherwise specified in the text. Further, elements, steps, operations, and / or elements mentioned in the specification do not preclude the presence or addition of one or more other elements, steps, operations, and / or elements.

Hereinafter, the configuration and operation effects of the present invention will be described in more detail with reference to the accompanying drawings.

2 is a cross-sectional view taken along the line I-I 'of FIG. 2. FIG. 4 is a cross-sectional view taken along the line II-II of FIG. 2. FIG. II 'line in Fig. 2, and Fig. 5 is a sectional view of the line III-III' in Fig.

In addition, the components of the drawings are not necessarily drawn to scale; for example, the dimensions of some of the components of the drawings may be exaggerated relative to other components to facilitate understanding of the present invention. In the meantime, the same reference numerals denote the same elements throughout the drawings, and for the sake of simplicity and clarity of illustration, the drawings illustrate a general constructional scheme and are intended to unnecessarily obscure the discussion of the described embodiments of the present invention Detailed descriptions of known features and techniques may be omitted so as to avoid obscuring the invention.

1 to 5, the common mode filter 100 of the present invention includes a primary coil layer 111, a secondary coil layer 112, an external terminal 120, a first ESD prevention member 131, A second ESD prevention member 132, and a ground electrode 140 as a basic structure.

The primary coil layer 111 and the secondary coil layer 112 are formed of a metal wire plated with a spiral coil pattern and made of silver (Ag), palladium (Pd), aluminum (Al) ), Titanium (Ti), gold (Au), copper (Cu), or platinum (Pt), or a mixture of at least two materials.

Although the primary and secondary coil layers 112 are stacked in the thickness direction at predetermined intervals, the primary and secondary coil layers 112 are alternately arranged in the same pattern Or the primary and secondary coil layers 112 may be formed of two or more layers to increase the number of coil turns.

The first and second coil layers 111 and 112 receive an external signal through an external terminal 120 connected to both ends. That is, the primary coil layer 111 is provided with a pair of external terminals 120 at both ends thereof and is electrically connected to the outside. Similarly, the secondary coil layer 112 has a pair of external terminals (120) is provided to energize the outside. Here, the external terminal 120 connected to one end of one coil layer may be an input terminal, and the other external terminal 120 may be an output terminal.

As described above, the primary coil layer 111 and the secondary coil layer 112, to which an external signal is applied via the external terminal 120 and are disposed adjacent to each other, form an electromagnetic coupling with each other, so that the primary coil layer 111 And the secondary coil layer 112, magnetic fluxes are strengthened to increase the common mode impedance to suppress the common mode noise, and when the current in the opposite direction flows, the magnetic fluxes cancel each other, The impedance is reduced, and the common mode filter that passes a desired transmission signal is operated.

The primary coil layer 111 and the secondary coil layer 112 may be disposed inside the insulating layer 110. The external terminal 120 may be formed on the insulating layer 110, And may be electrically connected to the first and second coil layers 111 and 112 through a via-electrode 113 penetrating through the via hole 110.

The insulating layer 110 functions to protect the first and second coil layers 111 and 112 from the external environment by imparting insulation to the first and second coil layers 111 and 112. Therefore, it is preferable that the insulating layer 110 is selected in consideration of the insulating property, the heat resistance, the moisture resistance, and the like. For example, as the optimum polymer material constituting the insulating layer 110, , Thermosetting resins such as phenol resin, urethane resin, silicone resin and polyimide resin, and thermoplastic resins such as polycarbonate resin, acrylic resin, polyacetal resin and polypropylene resin.

The insulating layer 110 in which the first and second coil layers 111 and 112 are embedded may be provided on the magnetic substrate 160.

The magnetic substrate 160 is a ferrite hexahedron fabricated in accordance with the horizontal and vertical sizes of the chip, and is disposed at the lowermost portion of the chip to support various structures of the chip including the insulating layer 110. Specifically, the magnetic substrate 160 may be composed of Fe-Ni-Zn oxide system, Fe-Ni-Zn-Cu oxide system, or metal ferrite such as Fe, Ni, Fe-Ni , So that it can function as a path of magnetic flux generated in the primary and secondary coil layers 111 and 112 together with the magnetic resin composite 150.

The first ESD prevention member 131 and the second ESD prevention member 132 may connect between the first and second coil layers 111 and 112 and the external terminal 120 that conducts electricity. 6, which is a top view of the common mode filter before forming the external terminal 120, the first ESD prevention member 131 is formed in a bar shape, And may be formed so as to be linearly connected between a pair of external terminals 120 to be energized. The second ESD prevention member 132 may also be formed in a bar shape so as to be linearly connected between the secondary coil layer 112 and a pair of external terminals 120 to be energized.

Here, the first and second ESD prevention members 131 and 132 may be formed of an insulating resin matrix in which various metal particles are dispersed. Specific examples of the resin material used as the matrix include polymer materials such as epoxy resin, phenol resin, urethane resin, silicone resin and polyimide resin, and metal particles include C, Ni, Cu, Au, Ti, Cr, Ag, Pd, and Pt, or a metal compound thereof.

Since the first and second ESD prevention members 131 and 132 having such a structure have an infinite resistance value in a normal operation state without the electrostatic pulse, a signal applied from the external terminal 120 is applied to the first and second coil layers 111 and 112, respectively. On the other hand, when an overvoltage due to static electricity is applied, an electron tunneling phenomenon occurs in which a conductive path is formed between the metal particles in the first and second ESD prevention members 131 and 132. As a result, Through the first and second ESD protection members 131 and 132 to the ground electrode 140 connected to the first and second ESD prevention members 131 and 132.

Particularly, in the present invention, the first and second ESD prevention members 131 and 132 are formed to connect between the pair of external terminals 120 connected to both ends of the coil layers 111 and 112, respectively. It can be discharged through the external terminal 120 or through the external terminal 120 as an output terminal regardless of its directionality.

The first and second ESD protection members 131 and 132 may be provided between the via electrode 113 and the external terminal 120, respectively. The first and second ESD prevention members 131 and 132 may be formed in the upper edge of the via electrode 113 and the first and second ESD prevention members 131 and 132 may be inserted into the first and second ESD prevention members 131 and 132, The side surface is buried in the insulating layer 110 and the upper surface is exposed to the outside of the insulating layer 110 to be bonded to the external terminal 120. Since the first and second ESD prevention members 131 and 132 formed in a bar shape are installed in the insulating layer 120 without occupying a separate layer, the common mode filter of the present invention is advantageous for realizing thinning and miniaturization. .

The ground electrode 140 may be provided to connect the first ESD prevention member 131 and the second ESD prevention member 132. 7, the first ESD prevention member 131 and the second ESD prevention member 132 are disposed in parallel with each other, and the common mode filter is formed in parallel with the common mode filter, The ground electrode 140 may be formed in the form of a bar and may be provided so as to cross between the electrodes in the form of a bridge.

According to such a configuration, an overvoltage signal flowing to one of the first and second ESD prevention members 131 and 132 can also be diverted to the ground electrode 140 connected to the other ESD prevention member. It has an advantageous advantage.

In addition, a step 140a may be formed at the center of the ground electrode 140. The magnetic resin composite 150 having a composition of ferrite and resin is provided around the external terminal 120 including the ground electrode 140 to smoothly flow the magnetic flux generated in the first and second coil layers 111 and 112 In the present invention, the magnetic resin composite 150 may be filled in a depression formed by the step 140a of the ground electrode 140, so that the magnetic flux in the present invention is smooth .

The stepped portion 140a of the ground electrode 140 may be formed at a position corresponding to the center core portion of the first and second coil layers 111 and 112. That is, since the center core portion of the first and second coil layers 111 and 112 is filled with the resin material of the insulating layer 110, the step portion 140a of the ground electrode 140 contacts the first and second coil layers 111 and 112 So that it can be embedded in the center core portion.

At this time, as the step height of the step 140a is increased, the recessed space due to the step 140a is widened, so that a larger amount of the magnetic resin composite 150 can be filled. However, And the risk of short-circuiting with the ground electrode 140 increases. Therefore, it is preferable that the step height of the step 140a is set appropriately in consideration of this.

The ground electrode 140 and the external terminal 120 may have the same thickness and the magnetic resin composite body 150 may have the same thickness as the ground electrode 140 and the external terminal 120. Accordingly, the upper surface of the external terminal 120 and the remaining portions of the ground electrode 140 except the step 140a are exposed to the outside of the chip, and these exposed surfaces can be bonded to one surface of the substrate when the substrate is mounted.

The foregoing detailed description is illustrative of the present invention. It is also to be understood that the foregoing is illustrative and explanatory of preferred embodiments of the invention only, and that the invention may be used in various other combinations, modifications and environments. That is, it is possible to make changes or modifications within the scope of the concept of the invention disclosed in this specification, the disclosure and the equivalents of the disclosure and / or the scope of the art or knowledge of the present invention. The foregoing embodiments are intended to illustrate the best mode contemplated for carrying out the invention and are not intended to limit the scope of the present invention to other modes of operation known in the art for utilizing other inventions such as the present invention, Various changes are possible. Accordingly, the foregoing description of the invention is not intended to limit the invention to the precise embodiments disclosed. It is also to be understood that the appended claims are intended to cover such other embodiments.

100: common mode filter of the present invention 110: insulating layer
111: primary coil layer 112: secondary coil layer
113; Via electrode 120: External terminal
131: first ESD prevention member 132: second ESD prevention member
140: ground electrode 140a:
150: Magnetic Resin Composite 160: Magnetic substrate

Claims (10)

A primary coil layer and a secondary coil layer that are electromagnetically coupled;
A pair of external terminals connected to an end of the primary coil layer and a pair of external terminals connected to an end of the secondary coil layer;
A second ESD prevention member connecting a first ESD prevention member connecting between the pair of external terminals to be energized with the primary coil layer and a pair of external terminals energizing the secondary coil layer; And
And a ground electrode connecting the first ESD prevention member and the second ESD prevention member, wherein a stepped portion is formed at the center of the ground electrode.
The method according to claim 1,
Wherein the first ESD prevention member and the second ESD prevention member are formed in a bar shape.
The method according to claim 1,
Wherein the ground electrode is formed in the form of a bar having a stepped portion at the center thereof.
The method according to claim 1,
Wherein a magnetic resin composite is further provided around the ground electrode including a recessed space formed by the stepped portion of the ground electrode.
A magnetic substrate;
An insulating layer provided on the magnetic substrate and provided with a primary coil layer and a secondary coil layer that are electromagnetically coupled to the inside of the magnetic substrate;
A pair of external terminals provided on the insulating layer and connected to ends of the primary coil layer via via electrodes, and a pair of external terminals connected to ends of the secondary coil layer;
A second ESD prevention member connecting a first ESD prevention member connecting between the pair of external terminals to be energized with the primary coil layer and a pair of external terminals energizing the secondary coil layer; And
And a ground electrode provided on the insulating layer and connecting the first ESD prevention member and the second ESD prevention member, wherein a stepped portion is formed at the center of the ground electrode.
6. The method of claim 5,
Wherein the first ESD prevention member and the second ESD prevention member are disposed in parallel, and the ground electrode is disposed across the first ESD prevention member and the second ESD prevention member.
6. The method of claim 5,
Wherein the first ESD prevention member and the second ESD prevention member are provided between the via electrode and the external terminal.
6. The method of claim 5,
Wherein the magnetic resin composite is provided around the ground electrode and the external terminal including a recessed space formed by the stepped portion of the ground electrode.
9. The method of claim 8,
Wherein the magnetic resin composite is formed at the same height as the ground electrode and the external terminal.
6. The method of claim 5,
Wherein a stepped portion of the ground electrode is formed at a position corresponding to a center core portion of the primary coil layer.

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